Page({
    data: {
        count: 1,
    },
    // 子组件传值会添加在e.detail对象里
    syncCount(e) {
        console.log(e);

        this.setData({
            count: e.detail.val,
        });
    },
    getChild() {
        const child = this.selectComponent(".childC");
        child.addCount();
    },
});